When I can find a suitable automatic trike with reverse gear and more rake on the forks I'll be parting with my beloved Gertie. Prolly won't be till after the summer tho unless something turns up!
Short arms isn't a problem, most trikes could be adapted with a change of bars. As Fourtoes said, you don't have to worry about putting your feet down (well only remembering NOT to!) just need to be able to reach the controls.
You should have had a sit on gertie at the weekend just to see about what size of trike it's worth going to look at, could have had a ride round the field too! (Mind you my hand gearchange takes a bit of getting used to, I'm told!).
Maybe we'll meet up sometimes soon, I believe you're somewhere down south? I'm in Dorset. Also might be worth a visit to
BB Customs in Ferndown, Dorset - Bruce built my trike before he got so busy and moved to the big posh unit!